Manufacture of pulp rovings



June 28, 1932. F. w. VOGELET AL I MANUFACTURE OF PULP ROVINGS- Filed June 6, 1951 rerouted June 28, 1932 STATES vrnrrzrrr orrice FEEDERIGK W. VOGEL AND WILLIAM MEGIITZ, OF BERLIN, NEW HAMPSHIRE, AS-

SIGNORS TO BROWN COMPANY, OF BERLIN, NEW HAMPSHIRE, A CORPORATION 01' MAINE MANUFACTURE 01' PUL? BOVINGS Application filed June 6, 1931. Serial 1T0. 542,648.

The subject of this invention is an imrovement in the manufacture of pulp rovings from comparatively short-fibered material, such as wood pulp. In the production.

of such rovings, it is the practice to start with an aqueous suspension of pulp and .to deposit the pulp fibers progressively from the aqueous vehicle as spaced, continuous ribbons or webs on a travelmg wire cloth such as used in a Fourdrinier papermaking machine. The pulp ribbons may be partially dewatered, as by suction, while-still on the wire, to a moisture content at which they are most amenable to furlingor rolling'out intorovings or strands of substantially uniiorm cross-section, tensile strength, softness, etc. While it is possible to remove the damp ribbons from the wire and to direct them through the atmosphere to furling mechanism of any suitable description, nevertheless it has been found most advantageous to effect their furling and compacting while they are still supported on the wire. Thus, when furling and compacting are carried out on the form wire, there is little danger .of rupturing or weakening the uniformly felted structure of the ribbons, or causing the ribbons to intermingle, even though they are damp and so tender as to be highly susceptible to spoilage.

@ne of the troubles which arises when the damp pulp ribbons are fur-led and compactnto rovings on the forming wire is that the; e is serious danger. of skipping or of in completely furling the ribbons, even when a friction roll, such as a wire-cloth-covered roll, is used as the instrumentality for engaging the ribbons and rolling them out into round form. N e have observed that this trouble is on account of the fact that pulp fibers become entangled in the forming wire and thus cause sticking of the ribbons as a whole to the wire so as to resist engagement of the t'urling roll with those edges which are to serve as the starters for the furling operation. In accordance with the present invention, before the furling operation, we

detach onlythese edge portions from the wire, so as to make positive the initiation and complete culmination of the furling operation. By detaching the edge portions on only one side of the ribbons, the ribbons are maintained against misplacement by those fibers on their opposite edge portions still in entanglement with the wire as a result of previous forming and sucking the pulp on the wire. This feature is of utmost importance, particularly in a machine where the continuous ulp deposits or ribbons are closely s ace on the forming wire so as to realize t e maximum production and where there is hence danger of causing snarls or intermingling between the ribbons during the furling operation.

With the foregoing and other features and objects in view, our invention will now be described in'conjunction with the accompanying drawing, wherein Figure 1 is a side elevation, partly in section, of a machine embodying our invention.

Figure 2 constitutes a front elevation of the machine.

Figure 3 represents a sectional detail on the line 33 of Figure 1.

While not limited thereto, the machine chosen for illustrating our invention is of the same type as that described in application Serial No. 542,649, filed June 6, 1931, by Milton 0. Schur and William B. Meglitz. That application discloses the principle of furling and compacting the pulp ribbons into rovings directly on the forming wire by means of a friction roll, preferab y a roll of the same general type as the so-called dandy roll used in paper manufacture, having an eiiective roving surface of relatively large diameter. As shown in Figure l, the wet-0r forming end of the machine may include a suction roll indicated generally by the numeral 1, and a pulp vat indicated generally by the numeral 2. A wire cloth or screen 3, such as used on a Fourdrinier machine, passes tightly about the roll 1, which is provided with spaced peripheral grooves (not shown) communicating with its interior so as to cause a deposition of pulp as spaced, continuousribbons when an aqueous pulp suspension is run onto the roll from the vat 2. The vat is made up of a bottom s and side walls 5. whose front edges terminate in close proximity to the roll, so as to direct a flow or" the pulp suspension onto the wire, the front edges 5a of the side walls being of an arcuate shape to conform to that portion of the roll periphery presented thereto. The roll proper is suported near its ends in suitable bearing memrs 6, and is rotated by suitable means (not shown), thereby serving to drive the wirein the direction indicated by arrow. The vat, only the front or delivery portion of which is shown, continuously receives a supply of pulp suspension of suitable consistency from a supply pipe (not shown). The suspension is delivered under a baffle plate or false bottom 7 which acts to confine the flow frontwardly. The pulp suspension flows onto the Wire, and the aqueous vehicle passes through the wire into the roll only over those areas or zones immediately in back of the spaced eripheral grooves, as aresult of which ribons of pulp are deposited on the wire. In

order that a uniformly textured or interfelted deposit of pulp be made, an excess of highly dilute pulp suspension is delivered into the vat, the excess taking the course indicated past the clearance or throat space 8 between the baflle and the roll, and thence over the bafile to the rear of the vat, where it is removed and returned to the source of supply. The pulp suspension employed may be of a consistency of only about 1/40%, or even less, -in which case large quantities of water are removed during the formation of the pulp ribbons. To this end, a suction chamber 9, occupying a sector somewhat reater than the periphery portion of the roll in contact with the pulp suspension, may be arranged inside of the roll, so as to accelerate withdrawal of the water from the pulp suspension and thus to promote the formation of pulp ribbons on the wire. The wire carrying the pulp ribbons out of the pulp suspension may then pass over a smaller second suction chamber 10 adjacent to the chamber 9. In depositing on the wire, the pulp fibers assume a preponderantly longitudinal lay, particularly when the wire is traveling at such speeds as 500 feet per minute, or greater.

A certain amount of cross-laying and random-laying of the fibers inevitably ensues, particularly onaccount ofthe turbulence and eddying of the pulp suspension as it flows through the clearance 12 and the currents of water cascading into the roll.

The wire carrying deposits of pulp ribbons proceeds horizontally from the roll 1 over the desired number of suction boxes 11 maintained under suflicient suction to dewater the ribbons to a water content of about 250% to 300%, more or less, based on the weight of fiber. At this water content, the ribbons are amenable to ready furling into rovings or round bodies; and, in accordance with our invention, the furhng action 1s made positlve,

uniform, and complete. To this end, the wire passes over a pressure box 12, wherelnto a gaseous medium under pressure, such as compressed air, is delivered by a pipe 13 from a pump or pressure chamber (not shown). The compressed air is emitted from the box as best shown in Figure 3, through a series of apertures 14 arranged transversely of the top 15 of the box with which the wire makes tight frictional contact. The apertures register with or subtend the edge portions on only one side of the ribbons, each air blast having the effect of progressivel lifting the edge portion of a ribbon from t 1e wire as the wire moves thereover, Without, however, weakening, rupturing, or dislodging the rib bons from thelr initial placement. In fact, the lifting is only temporary and merely de-' taches the edge portions of the ribbons from the wire, so that the initiation of the subse quent furling or convoluting action there; upon is rendered easy and positive. The wire then passes over a guide roll 16, whence it takes a vertically downward course to a spaced guide'roll 17. The vertical wirestretch 18 between the rolls 16 and 17 is where the furling can be most conveniently accomplished. For this purpose, a furling dandy roll 19, whose periphery is covered with wire clothof, say, 40 or finermesh, is shown in engagement with the confronting stretch 18 over an appreciable arc of contact, the axis of the roll being inclined at an angle of, say, 80, more or less, to the direction of travel of the wire and the ribbons supported thereon. The wire-cloth covering may be fixed, as by welding, to a series of spaced rings 20, con stituting the rims of spiders 21 and anchored to the shaft 22 for the roll. The roll shaft may be journaled for rotation in a pair of brackets 23 extending from a transverse bar 24 toward the wire 18. As the pulp ribbons, indicated by the numeral 25 in Figure 2, enter the nip of the wire 18 and the roll 19, the relative angular movement between the wire and the roll causes a furling or lateral rolling out of the ribbons into round form, with the edge portions previously detached from the wire affording an eas furling start, particularly as the damp rib one are pliable and v of a quasi-dough-like consistency. .The furling roll may be positively driven, although, I

scribed and claimed in application Serial No.

504,029, filed December 22, 1930, by Milton 0. Schur. After collection, the rovings may be twisted. plied into yarns or strings, and dried. Provision is preferably made to vary the angle of inclination of the furling roll 19, for which purpose the bar 24 may have a centrally located pivot pin 27, normally fixed at its outer or threaded end by a nut 28 tothe cross-member 29 of a pair of spaced standards 30. If desired, bolts 31, positioned near the ends of the bar 24, may project through arcuate slots 32 in the cross-member 29, so as to permit firm fixture of the roll to the crossmember by nuts 33. In adjusting the angu larity of the roll, the three nuts are loosened, and, after the roll has been swivelled to the desired angularity, the nuts are tightened down against the member 29. In returning to the suction roll 1 from the roll 17 the wire takes an. inclined upward course over the tightening roll 34 and then runs substantially horizontally over a guide roll 35 to the suction roll.

The combination of instrumentalities described is subject to modification, particularly depositing the pulp ribbons from aqueous suspension on the wire and the mechanism for furling the ribbons, although the assembly of the vat, suction roll, forming wire, and furling roll has been found to give excellent results in actual practice. We do not, however, claim these variousfeatures per se or in combination, except in so far as they enter into our invention. Our invention, as already indicated, devolves about the detachment of the edge portions on only one side of the ribbons deposited on the forming wire, so that furling or roving of the ribbons directly on the wire may be positively and uniformly efiected to completion with little, if any, liability of damaging or destroying the uniformity of texture or formation realized at the wet end of the machine, and with little, if any, danger of snarling or intermingling the ribbons during furling or roving, even when they are as closely spaced as to 4 inches apart. -By positive and uniform furling action, we mean that there is a greatly reduced tendency for the roll to miss or skip engaging the detached edge portions of the ribbons, and, as a result, there is secured the desired convolution of the ribbons into round bodies or strands entirely free from raggedness or lines of cleavage in their structure.

What we claim is:

1. A method which comprises progressively depositing from aqueous suspension pulp fibers as ribbons on a traveling wire cloth, progressively detaching the edge poras regards the means for forming or,

damp ribbons into round form at an angle to the direction of travel of the wire.

3. The combination with a traveling wire cloth and means for progressively depositmg from aqueous suspension spaced r1 bons of pulp on said cloth, of means for detaching the edge portions of the ribbons on only one side from the cloth and means for engaging the detached edge portions and furling the ribbons into round form while on the wire.

4. The combination with a traveling wire cloth and means for progressively depositing from aqueous suspension spaced ribbons of pulp on said cloth, of means for delivering blasts of gaseous medium under the edge portions of the ribbons on only one side to'lift said edge portions from the cloth and a roll frictionally engaging said cloth and ribbons and arranged at an angle of inclination to the direction of travel of said cloth so as to engage the lifted edge portions and roll the ribbons into round form.

5. The combination with a traveling wire cloth, means for progressively depositing from aqueous suspension spaced ribbons of pulp on said cloth, and means for partially dewatering said ribbons .on said cloth, of means for delivering blasts of gaseous medium under the edge portions of the ribbons on only one side to lift said edge portions from the cloth and a roll whose periphery is covered with wire cloth frictionally engaging said traveling cloth and ribbons and arrang at an angle of inclination to the direction of travel of said cloth so as to engage the lifted edge portions and roll the ribbons into round form. v

In testimony whereof we have afiixed our signatures.

FREDERICK W. VOGEL. WILLIAM B. MEGLITZ.

tions of the ribbons on only one side from i the wire, and frictionally engaging the detached edge portions and rolling out the ribbons into "round form while still-on the wire.

2. A method which comprises progressively depositing from aqueous suspension pulp fibers as ribbons on a traveling wire cloth, only partially de'watering. said ribbon on the wire, progressively detaching the edge portions of the ribbons on only one side from the wlre, and frictionally engaging the detached edge portions and rolling out the 

